I have a 99 accord sedan and i have the following set up, 1200.1 jbl amp. 2 10inch HE2 fosgate subs. i have 4 gauge power cable and 6 gauge ground coming from the bolt thats on the latch that the trunk locks on too when you close it. i used to have a power acoustic 600 watt amp on it and no problems. so i put in the 1200 watt jbl and all of a suden when i put the volume up the fuse blows. i blew 2 80 A fuse already the fuse that is on the 4 gauge power wire from the battery to the amp. can anyone tell me if its a problem? should i get a stronger fuse or what can i do to fix this. capasitor? thanks for the help also i have alot of annoying engine noice on my highs only.how can i help this? thanks alot for the info

 

DAMN! 6 gauge wire for a ground?!? shit...you need to match your ground wire to the size of your power wire. About the fuse situation, you might try a 100AMP ANL fuse.

 

what size is the other amp and what wire do you have running to it? Get a better ground to fix the alternator whine.

 

same wires were ran to both amps. and i tried running around the whole trunk looking for good ground and it dont work.

 

same wires were ran to both amps. and i tried running around the whole trunk looking for good ground and it dont work.

 

a 4 ga wire is too small for more then just the 1200 to begin with. It's no wonder that you are breaking fuses. The largest I would go on that run of wire is about a 100A fuse...anything past that, and you are pushing the capacity of the wire. I would consider running a second line of 4 or 8 ga to the second amp (depending on it's size) and fusing both lines appropriately.

There are plenty of good grounding areas in the trunk, you just have to make sure that you keep them short, sand down to bare metal (not primer) and make sure it's on there tight.

 

A 4ga wire transferring 100amps will drop 5% of it's current over a 12ft run, or about .7 volts. 4ga can sustain 135 amps over short runs (under 20ft) with no issues. If you want to know why you're blowing fuses, don't look to the wire-- voltage drop doesn't blow fuses. You won't need to step to a huge wire gauge until you're good and well past 2000 watts RMS.

I'm running a Fosgate 400a4 and 800a2 off of a single 4ga from battery back, and have never had fuse or voltage dip problems (135a alternator). There's no need to include a main power line with more capacity than your entire charging system.

 

hehe...must have been all that spray glue I've been inhaling while working on the car....

yes, wire size doesn't contribute to broken fuses - I really didn't intend to say that. Essentially a broken fuse means that you are asking for more current then the fuse will pass. This could be because of a short, or because the amps are thirsty.

At full tilt, your 1200.1 will draw 120A - but because of the duty cycle of music, you will rarely hit that unless you are doing burps or sine sweeps.

My point is that I don't find even 0.7V of drop acceptable simply due to the internal resistance of the wire. (one reason I'm running 0/1 in my car ). I would suggest you select a 120A fuse and go from there. I'd consider, at that length (approx 12 feet) that 4 ga is safe to around 120A (don't know where 100A came from either...inhaling glue is bad m'kay ).

Then again, I always err on the side of caution - wire is cheap.

 

Well said! :thumbup:

 

umm if i get a 2 gauge for the ground right about 1.5 to 2 feet long . run that to a Distribution Block and then split the ground to 2, 4 gauge wire to the amps would that be ok?